JOURNALOF Economic Behavior Journal of Economic Behavior and Organization & 0 ~ll~ ELSEVIER Vol. 29 (1996) 323-329 Changing a decision taken under incomplete information during the process of execution Gil S. Epstein * Department of Ectmomics. Bar.llan University. Ramat Gan 52900. Israel. Received 10 January 1994; revised 27 September 1994 Abstract When making decisions in a situation of uncertainty such as investments, R and D, pricing etc., there is always the possibility of choosing the wrong action. This study deals with a case where decisions are made under uncertain conditions. While implementing the decision, we may receive information about the unknown and update our expectations. Changing the decision while carrying it out is costly. In this study we show that there are sufficient conditions, at the time of making the first decision, to realize that one will never want to change it. Some of these conditions depend only on the distribution of the random variable and do not depend on the cost function. JEL classification: D4; L I; L2 Keywords: Uncertainty; Decisions; Information 1. Introduction Scarcity implies that choices must be made, and making choices implies the existence of costs. Every time a choice must be made, opportunity costs are incurred. Making decisions is not always an easy task and yet, we make decisions " Corresponding author. 0167-2681/96/$15.00 © 1996 Elsevier Science B.V. All righls reserved SSDI 0167- 2 68 ! (95)00066- 6